The present invention describes improved drawing compounds useful for steel and aluminum or other like metals. In a drawing or stamping operation, a great deal of heat is produced at the boundary interface between the draw and the drawing apparatus. To reduce the effects of heat, liquid compositions have been utilized at the interface. In the past, water based chemistry has been utilized and hydrocarbon oils based chemistry has been utilized. In this invention, high-viscosity hydrocarbon oils in the form of a micro-emulsion are used. Such a micro-emulsion contains about 2 to 30 percent of 500 to 3,000 s.u.s. hydrocarbon oils and a base of emulsifiers and stabilizers. The drawing fluid produced by this invention is a micro-emulsion wherein the colloidal particles are one micron or below. These micro-emulsions are emulsions containing particles as aforesaid which are limited to one micron or 10.sup.6 for at least one particle dimension. These micro-emulsions may be produced by acid hydrolysis and agitation. In this particular invention, the emulsions are produced in the form of water-in-oil emulsions which, upon contact with excess water, invert and become oil-in-water emulsions. The micro-emulsion particles are characterized by enlarged surface area-to-volume relationship and they do not settle out and are small enough to sift out through filter membranes. These micro-emulsions show good coefficients of friction indicating high values for lubricity and have good coolant qualities when utilized in drawing operations. They are also known as semi-synthetic drawing fluids where water is incorporated and utilized as a portion of the emulsion as in the straight oil usually used.
In a second portion of the invention, the high-viscosity hydrocarbon oils are exchanged with ethoxylated vegetable oils, for example, ethoxylated castor oil. Other oxides, such as ethylene oxide, propylene oxide and ethylene oxide/propylene oxide copolymers may be utilized. It has been found that about 4 to 30 moles of the ethylene oxide and related compounds may be utilized as the oxidized fraction of the vegetable oil and in the repeating units. In this portion of the invention, the semi-synthetic of the micro-emulsion oils is changed to interchanging the high-viscosity hydrocarbon oil with an ethoxylated vegetable oil, such as castor oil, producing a synthetic.
The vegetable oils which are triacetyl glycerides may be selected from a variety of vegetable oils, such as corn, cottonseed, palm, peanut, soybean and olive. The vegetable oils also are known as fats in other descriptions and they are derived from fatty acids of C.sub.3 to C.sub.24 carbon atoms and all are from even-numbered carbon atoms, except C.sub.3 and C.sub.5 derivatives. A preferred range of carbon atoms in from C.sub.12 to C.sub.24. The lubricant base for these vegetable oils in the micro-emulsion is similar to that for the natural hydrocarbon oils and may be emulsifiers and stabilizers selected from tall oil fatty acids and triethanol amine soaps, petroleum sulfonates and non-ionic emulsifiers.
In addition to an ethoxylate vegetable oil or hydrocarbon oil, the water-in-oil emulsion may contain under the heading of stabilizer, water-in-oil surfactants and like, and material such as triethanolamine, EO/PO tall oil acid ester, sodium petroleum sulfonate (5-15% of the micro-emulsion) and a C.sub.12 -C.sub.24 fatty acid amine soap, a non-ionic alkoxylated coupling agent (3-7% of the micro-emulsion), and a low degree alkoxylated vegetable oil (0-10% by weight of the micro-emulsion).
In the above, lubricants resulting from the two branches of the invention are described, namely, the natural hydrocarbon oils, on the one hand, and the vegetable oils, on the other hand, utilizing drawing and stamping compositions. Since the preparation of similar micro-emulsions is well known in the art and may proceed from several methods, further teaching of this process will not be necessary. The particular method utilized here is to prepare the water-in-oil emulsion under processes similar to that of Anderson and Frisque, (Nalco Chemical Company), see Example 2, and then invert with the addition of water to produce the final usable oil-in-water emulsion. Also, there have been described the compositions and the area of use, but a description of the draw and the metal-working apparatus is believed to be unnecessary, since it is well known and has been used many times before. It is to be noted that all of these compositions avoid the use of chlorine which has been found to be corrosion correlating as a gas or liquid.
A specific formulation for a composition involving oxidized castor oil is set out below.
4.5% ethoxylated (5-6 moles) carboxy-4-hexyl-2-cyclohexene octanoic acid (caster oil); PA1 6.3% tall oil; PA1 2.7% triethanolamine; PA1 1.8% EO/PO tall oil acid ester; PA1 9.0% sodium petroleum sulfonate; PA1 2.7% EO/PO polymer; PA1 18.0% caster oil ethoxylate (25 moles); PA1 50.35% D.I. water; PA1 4.5% polyglycol, alkanol amine mixture; PA1 0.15% triazine.
In other examples the percent of caster oil ethoxylate was varied to 2 to 30 percent. Cottonseed and soy bean oil were utilized as examples in similar percentages, by specific percentages of 2, 4.5 and 20 percent s.u.s. hc. were used. In addition, where the active ingredient was 500 to 3,000 s.u.s. hydrocarbon oil, similiar examples were used with 2, 4.5 and 20 percent hc. oils of 500, 1000 and 2000 s.u.s. The emulsifiers and stabilizers were varied according to the teaching further in this invention, describing water-in-oil type emulsifiers.
It has been stated above that the oils, water and emulsions generally have been described in the prior art.
Additional prior art in this area is listed below:
U.S. Pat. No. 3,501,404 to Klieber et al, Union Carbide, which discloses an aqueous emulsion containing an emulsifier and polymer in the range of 1,500 to 25,000 s.u.s. and the polymer being present in 0.1 to 25 percent of the emulsion;
U.S. Pat. No. 3,634,245 to Meisters, Kerns United Corp., which discloses a water-soluble lubricant product obtained by transesterifying a triglyceride, for example, caster oil, with a polymeric alkylene oxide glycol and then esterifying the hydroxy compounds present with a dicarboxylic acid;
U.S. Pat. No. 4,111,820 to Conti, which relates to drawing wire through a die, etc., and utilizes polyethylene oxide and a dispersant which may be polypropylene/glycol as a die lubricant;
U.S. Pat. No. 4,452,711 to Laemmle, describes an aqueous metal-working lubricant comprising a water-soluble mix of polyoxypropylene, polyoxyethylene, polyoxyethylene/propylene block copolymers, a water-soluble carboxylic acid, a water-soluble alkanol amine and water used for cold-rolling and hot-rolling a metal such as aluminum and aluminum alloys.
It is believed that the present invention here differs from the prior art and contains elements which are new and useful.
It is also possible to further characterize the water-in-oil emulsions of water-soluble vinyl addition polymers with respect to the aqueous phase of the emulsions. This aqueous phase is generally defined as the sum of the polymer or copolymer present in the emulsion plus the amount of water present in the emulsion. This terminology may also be utilized in describing the water-in-oil emulsions which are useful in this invention. Utilizing this terminology, the aqueous phase of the water-in-oil emulsions of this invention generally consists of 25-95% by weight of the emulsion. Preferably, the aqueous phase is between 60-90% and most preferably from 65-85% by weight of the emulsion.
The emulsions also may be characterized in relation to the water/oil ratios. This figure is simply a ratio of the amount of water present in the emulsion divided by the amount of hydrophobic liquid present in the emulsion. Generally, the water-in-oil ratio is 0.25 to 18. Preferably, the water-in-oil ratio will range from 0.3-14, and most preferably from 1.0-2.75.